The U.S. Army Mobility Equipment R&D Center embarked on an overall program to reduce noise of construction equipment as a result of the low noise level requirements established by the Army Surgeon General. Since the level was interpreted to be the overall average noise, it was necessary to measure average noise and define a means of test as well as to design equipment to lowest possible levels.
The initial program was to analyze the source of noise, reduce noise at the source, and provide overall noise reduction treatment to reach lowest practical levels. Similar efforts were then accomplished on several special military vehicles to provide noise reduction retrofit kits.
The initial work revealed special needs in the area of hydraulic system noise, and acoustical materials and in-depth studies were initiated to analyze techniques of hydraulic noise measurement and to evaluate material suitability for military use.
Tests were run on items of construction equipment during actual field operations to develop a system of measuring average noise. The results will be used to evaluate equipment noise in specifying practical levels.